The Tánaiste has pledged new laws to allow "urgent and critical pieces of infrastructure" to be built without being hampered by the traditional legal, bureaucratic and financial impediments.
In an interview with The Irish Times at the end of her party's annual conference in Galway, she also pledged unequivocally to lead the Progressive Democrats into the next general election.
This follows speculation that she would leave her post earlier.
Ms Harney said road and rail projects in Ireland were often five times as expensive and took much more time than equivalent projects in mainland Europe.
The reasons, she said, were the huge compensation bills paid here for "disruption, the high cost and long process of buying land and other bureaucratic obstacles".
With the Government saying it has no extra money to fund a Dublin Metro or the Strategic Rail Initiative, Ms Harney said: "We need to urgently reform the manner in which we set about doing big projects. Major rail projects are just not affordable unless we change legislation. There is a necessity for urgent and critical pieces of infrastructure to have new laws to facilitate them."
She also said there should be competition both at Dublin Airport and between the State's airports, signalling support both for a private terminal at Dublin and the break-up of Aer Rianta.
She said Aer Lingus had increased its traffic by 11 per cent with a third fewer staff. She wanted competition on bus routes as well.
"It is chilling to note that with the exception of engineers, there is no competition in any professions".
She said the Government would work to remove barriers to entering many professions.
She said the greatest ever reform of the insurance market would result in prices beginning to come down within a year.
The process of moving large blocks of the public service out of Dublin would also begin within a year.
In relation to her future as party leader she said: "It is my intention to lead the party into the next general election."